Showing items related by title, author, creator and subject.

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  Mangrove structure and mud crab population in northern Samar 

  Quinitio, Emilia T. ; Vista, Evelyn B.; Vista, Rafael C.; Lebata-Ramos, Ma. Junemie Hazel (Aquaculture Department, Southeast Asian Fisheries Development Center, 2017)

  This study assessed the mangrove community structure, relative seasonal abundance of all size classes of crabs (catch per unit effort or CPUE) and percent composition of the catch in two collection grounds in Pambujan and Rosario, Northern Samar using cylindrical bamboo traps and lift nets. Mangroves in Pambujan was dominated by Avicennia marina and A. alba. The initial total count of mangrove trees (67 stems ha^-1) was slightly higher compared with the final count (61 stems ha^-1). On the other hand, mangroves in Rosario was dominated by Rhizophora apiculata and R. stylosa. The total count of mangrove trees was higher in the initial (108 stems ha^-1) compared with the final (46 stems ha-1). However, saplings and seedlings increased in both sites after 18 months. Mean CPUE ranged from 0.04 to 0.4 crabs using cylindrical bamboo traps in the monthly spring tide sampling for 19 months in Pambujan. High mean CPUE was recorded in February and August 2008. Mean CPUE ranged from 0.04 to 0.41 crabs using lift nets in the monthly spring tide sampling. The highest mean CPUE was noted in August. The initial and final CPUE were comparable. In Rosario, mean CPUE ranged from 0.3 to 1.78 crabs monthly caught in cylindrical bamboo traps and from 0.04 to 0.77 crabs in lift nets. In general, the number of crabs caught in both traps was higher in Rosario than in Pambujan. Mud crab ranged from 2.02-72.2% of the monthly total catch in lift nets in Pambujan. Other species of crabs ranging from 27.78 to 86.36% were the dominant catch in several months. In Rosario, mud crab ranged from 12.5 to 82.35% of the monthly total catch. The catch composition of the cylindrical bamboo traps was more varied compared with lift nets in both sites. The decrease in the population of mud crabs may also be associated with the decrease in mangrove trees. With the continuous cutting of trees and regular extraction of all sizes of mud crabs, the industry may no longer become sustainable. This paper is the first to be done on the assessment of the mud crab population in Northern Samar and the information gathered can be used as basis for the development and improvement of the existing fisheries legislation for the conservation and management of the remaining wild resources.
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  Field guide to Philippine mangroves 

  Primavera, Jurgenne (Zoological Society of London-Philippines, 2009)

  Awareness of mangrove importance, particularly for coastal protection, has grown among the general public over the past several years. In turn, this has led to numerous planting initiatives by various groups. However, most ...
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  Distribution pattern of shrimps and fish among Avicennia and Rhizophora microhabitats in the Pagbilao mangroves, Philippines 

  Rönnbäck, Patrik; Troell, M.; Kautsky, N.; Primavera, Jurgenne (Elsevier, 1999)

  For sustainable management of mangrove ecosystems, there is a pressing need to increase our knowledge of fish and invertebrates associated with this system. This study sampled microhabitats (89–258 m²) inside the mangrove forest at Pagbilao, the Philippines, on two consecutive spring tides using stake nets. Distribution patterns of shrimps and fish were compared among four microhabitats that differed in dominant mangrove species (Avicennia marina, A. officinalis or Rhizophora apiculata), structural complexity of the root system, and proximity to open water habitat. A 5 to 6-year-old replanted Rhizophora microhabitat was also sampled to study faunal recolonization following replantation. The mean (±SE) density of the shrimp community was 1·5±0·2 shrimps m⁻², dominated by Palaemonidae, followed by Acetes sp., Penaeus merguiensis and Metapenaeus ensis . The highest shrimp density was observed in the replanted Rhizophora habitat, which also had the highest structural complexity. The mean (±SE) density and biomass of the fish community was 5·1±2·0 fish m⁻²and 10·4±3·3 g m⁻², respectively, dominated by Ambassis kopsi, A. urotaenia and Atherinomorus balabacensis. The fish community preferred the pneumatophore (Avicennia) microhabitats to the prop root (Rhizophora) habitats. Highest fish abundance and biomass were observed in the most inland habitat, which also lacked larger (total length >100 mm) carnivorous fish. The results demonstrate the extensive use of intertidal mangrove forests by vagile fauna, as well as the successful recolonization by shrimps and fish of replanted Rhizophora habitat. The role of mangroves as predation refuges, based on the distribution pattern of shrimps and fish, is discussed. Sampling strategies in mangrove intertidal habitat are also outlined.